Generally, recent mobile communication systems have a tendency to divide a base station into a digital unit (DU) and a radio unit (RU) so as to reduce operating expenditure (OPEX) and capital expenditure (CAPEX). That is, the signal exchange between the DU and the RU has used a fast serial interface (for example, an optical interface such as CPRI or a SerDes technology such as rocket IO).
One base station transmits and receives several frequency bands and may often use multiple input multiple output (MIMO) so as to increase channel capacity.
According to the current tendency, there is a need to exchange different signals for each antenna or each frequency in exchanging a signal between the DU and the RU, which results in linearly increasing a signal data amount in response to the number of antennas and the number of frequencies.
However, the serial interface between the DU and the RU actually has a limited transmission rate. As a result, when intending to transmit and receive data at a highest transmission rate or more, a serial line needs to be additionally used and costs are correspondingly increased due to the use of the additional line.
Therefore, there is a need for a method for reducing a data amount transmitted and received from and to the serial interface between the DU and the RU.